German police have detained former cyclist and Tour de France champion Jan Ullrich for allegedly attacking and injuring a woman in a Frankfurt luxury hotel, a police spokesperson said.

Ullrich was under the influence of alcohol and drugs when police detained him on suspicion of assault causing grievous bodily harm, spokesperson Carina Lerch confirmed.

Ullrich, 44, and the woman had an argument in the Villa Kennedy hotel in the early hours of Friday morning, Lerch said, adding that the woman needed medical treatment.

In an interview earlier this week, Ullrich had told German newspaper Bild that he had marriage problems and was emotionally stressed after his wife had decided to separate. He said he had not seen his three sons since Easter.

The 1997 Tour de France winner had just flown to Frankfurt from his home in Mallorca, where he had been involved in an altercation in the garden of his neighbour, German action film star Til Schweiger, last weekend.